In the spatial stabilization apparatus, a fixed part and one or more controlled objects are series-connected through connection parts that each has a rotation axis where the rotation angles of the connection parts are controlled.
An example of a spatial stabilization apparatus is described in PTL 1. The spatial stabilization apparatus of PTL 1 includes an outer gimbal and an inner gimbal, as controlled objects, an outer torquer, an inner torquer, an outer servo amplifier, and an inner servo amplifier. The outer torquer drives rotation of the outer gimbal in relation to the fixed part. The inner torquer drives rotation of the inner gimbal in relation to the outer gimbal. The outer servo amplifier outputs a drive signal of the outer torquer. The inner servo amplifier outputs a drive signal of the inner torquer. The outer gimbal is connected to the fixed part in a manner rotatable around a rotation axis. The inner gimbal is connected to the outer gimbal in a manner rotatable around a rotation axis and fixed to a payload. The direction of the rotation axis of the outer gimbal is the same as the direction of the rotation axis of the inner gimbal.
PTL 1 describes two configurations (hereinafter, referred to as “Configuration 1” and “Configuration 2”).
In addition to the above-described configuration, Configuration 1 further includes an inner inertial sensor that detects a rotation angle around the rotation axis of the inner gimbal in relation to the inertial coordinate system and an angle sensor that detects a rotation angle of the inner gimbal in relation to the outer gimbal.
Configuration 2 further includes, in addition to Configuration 1, an outer inertial sensor that detects a rotation angle around the rotation axis of the outer gimbal in relation to the inertial coordinate system.
The spatial stabilization apparatus of PTL 1 operates as follows.
In both Configuration 1 and Configuration 2, the inner servo amplifier is input the output from the inner inertial sensor, drives the inner torquer based on the output from the inner inertial sensor, and controls the rotation angle of the inner gimbal in relation to the outer gimbal.
In Configuration 1, the outer servo amplifier is input the output from the angle sensor, drives the outer torquer based on the output from the angle sensor, and controls the rotation angle of the outer gimbal in relation to the fixed part.
In Configuration 2, the outer servo amplifier is input the output from the outer inertial sensor and the angle sensor, drives the outer torquer based on the output from the outer inertial sensor and the angle sensor, and controls the rotation angle of the outer gimbal in relation to the fixed part.
As the result of the above operation, in the case of Configuration 1, having feedback from the inner inertial sensor, the inner gimbal is spatially stabilized using the inner servo amplifier.
Whereas, in the case of Configuration 2, having feedback from the inner inertial sensor, the inner gimbal is spatially stabilized using the inner servo amplifier. Further, in the case of Configuration 2, having feedback from the outer inertial sensor, the outer gimbal is further spatially stabilized using the outer servo amplifier, increasing the spatial stability.